'The Mortal Instruments': 7 Music Moments From the New YA Adaptation

Composer Atli Örvarsson reveals his themes for Clary and archvillain Valentine -- and how he scored that greenhouse scene.

Much as magical runes appear to The Mortal Instruments: City of Bones’s heroine Clary Fray (Lily Collins), Clary’s theme came to composer Atli Orvarsson during one of his first screenings of the film. “I immediately heard the idea of a lot of bells and tinkling metal,” he says. “In the dark, I started scribbling it down on a regular notepad.”

Orvarsson had to work quickly. City of Bones director Harald Zwart was so impressed with his score to Hansel & Gretel: Witch Hunters that he hired the composer immediately after the film’s January premiere, giving Orvarsson only nine weeks to write the City of Bones score and record it in London -- much less than the months or year Orvarsson sometimes has. “It was kind of a blessing and a curse,” he says. “There simply was no time to second guess.”

But he had no trouble finding a tone for the Cassandra Clare YA novel adaptation, in theaters on Wednesday -- the score is sepulchral, mystic, but with some “major key magic," says Orvarsson, “This film knows what it is and knows what it wants to be.” And the care Zwart took with the music was a saving grace for the composer. “He would literally make picture changes so I could finish a melodic phrase. He’s just the composer’s dream director,” Örvarsson says. Zwart also played all the Bach piano music in the film (which suggests Johann Sebastian was himself a demon-fighting Shadowhunter.)

Örvarsson told THR about the musical moments to listen for in the fantasy adaptation. [Warning: contains spoilers from the film and Cassandra Clare’s novel City of Bones.]

The Mortal Cup: “The Mortal Cup theme sounds like ancient music ... The first time you really hear it in its purest form, it’s played on an old, old instrument, the predecessor of the modern string orchestra, called a viol. I found a gentleman who plays with an early music ensemble and they play this instrument. It’s a very metal-sounding violin, and it’s usually played without vibrato, so it’s got a very piecing, pure tone.”

The City of Bones: “What’s happening when you see the City of Bones is there’s two melodies playing at once -- it’s Clary’s theme and the Mortal Cup theme. It’s the legend of the Shadowhunters and their history and all that, and we’re trying to depict or convey Clary’s awe, the experience of seeing this magnificent city that we don’t really see. The beginning of that piece, when they’re walking into that underground bunker, that has its own rhythmic thing, and it all has its big crescendo when the Silent Brothers are able to rekindle her memory.”

Clary and Jace’s love theme: “There’s a simple piano version, and then there’s a big string arrangement, and there’s a major and a minor key version. There is a scene where Jace and Clary and Simon encounter and kill a demon who is disguised as Madame Dorothea, and [Clary] has to choose between who she hugs and finds comfort with, and she goes with Simon, and the camera goes to Jace. I play the love theme in a minor key, the unattainable, lost-love version of it.”

The greenhouse: “I used a love theme there, through Jace’s story, and I think they found a really graceful way to segue into the song that Diane Warren wrote for it [‘Heart by Heart,’ sung by Demi Lovato] ... It’s more piano and bells and sort of atmospheric. It’s a very sparse version of the love theme.”

Valentine’s theme: “I always felt that he needed to have sort of a Darth Vader theme ... The Valentine theme is like a bolero, a bass line that keeps building and building. I used that when he comes out of the portal and he and Hodge are plotting and talking. While we were recording, our engineer had a great idea. He said, ‘let’s rent out a Minimoog synthesizer, and you should play his bass on this old synthesizer.’ It’s got this old, fast bass sound.”

Clary’s reunion with her mother: “I played the love theme there, which obviously most of the time is reserved for Clary and Jace. But because of what has transpired in the film, with Valentine putting the idea in their heads that they’re brother and sister, Clary sort of puts the question to her mom ... It was one of those happy accidents where I decided to try it and see how my sketch of that theme worked over that scene, and it did.”

Jace: “Jace doesn’t really have a theme -- he has sort of an action motif, because he tends to come and save the day.”